Boruto fans were treated to brand new fights in the tournament round of the Chunin Exams as Boruto: Naruto Next Generations continued on past the tournament round's original stopping point in Boruto: Naruto the Movie.
Along with changing the stopping point of the tournament, the series has also made a major change to Mitsuki's sage powers as they confirm that's it's more of a transformation rather than the "Sage Mode" Naruto uses.
In his fight with Gaara's strong son Shinki, Mitsuki struggles to land a worthwhile hit as Shinki proves his veil of Iron Sand acts much in the same way as Gaara's used to. It's defense and offensive power is so strong, it even gets Mitsuki to consider battling seriously as using, as he refers to it, his "Sage Transformation."
With the phrase "Sennin ka" Mitsuki confirms his power is a "Sage Transformation," as opposed to when it's normally featured "Sennin Moto" or "Sage Mode." This will definitely come as a blow to Mitsuki fans wondering about his strength, but since this is only a borrowing of the Sage Mode power in a transformation it explains a few things as well.
After Mitsuki surprisingly surrenders to Shinki, he thinks to himself that he might not have even won if he had used the transformation and fought seriously. Fans were wondering why he would assume his power wouldn't be enough, but if it isn't a full on "Mode" like Naruto has, then it explains his doubts.
Mitsuki's sage powers were first introduced in an episode detailing his past with Orochimaru. In the episode, Mitsuki, having lost his memories, wakes up with Orochimaru. Orochimaru tells him he had previously failed a mission attempting to take down a mysterious ninja named Log. But during the mission, he soon discovers that Log is actually an older Mitsuki.
"Log" then tells Mistuki that he is the latest in a line of attempts from Orochimaru to create a strong warrior, and that he is trying to save Mitsuki from sharing his fate as well. Orochimaru then confronts Mitsuki and tells him to choose between helping "Log" or continuing to follow Orochimaru's orders.
But Mitsuki is so angered by this betrayal he activates a secret power within him, an ability to use a Sage transformation, which Orochimaru was trying to teach him through this arduous mission.
For those unfamiliar with Boruto's predecessor Naruto, it has quite a storied history. Originally created by Masashi Kishimoto, the series ran in Shueisha's Weekly Shonen Jump for 700 chapters. The story follows Naruto, a young ninja with a sealed demon within him that wishes to become the leader of his home village. The sequel, Boruto: Naruto Next Generations is set several years after the events of the original Naruto story and featuring the children of many of its key characters such as Naruto and Hinata.